1. Field of the Invention
The present invention relates to a slide fastener, and in particular to a bottom stop assembly of a slide fastener with a separable bottom stop assembly.
2. Description of the Related Art
A separable slide fastener comprises two stringers which are completely separable. One of the stringers carries the slider permanently, and has at its bottom end a bottom end stop which incorporates an open box. The open box receives the bottom end stop of the other stringer, when the user closes the fastener.
Typically the two stringers are sewn to each side edge of an opening of an open and close article such as a bag, a garment, or the like. The open box is relatively bulky and can interfere with the sewing process. In order to avoid this problem, there are various open box designs in which the box can be firmly attached as being snap fitted onto a box pin fixed to the stringer, after the stringer has been sewn in an appropriate place of the above-described open and close article.
In DE-PS-626241, saw like teeth on the box pin engage in cooperating holes provided in the front and back walls of the box. Such a fixing impairs the appearance of the box as the teeth are exposed from the cooperating holes.
U.S. Pat. No. 4,112,553 describes an open box which has saw like teeth on the internal faces of the front and back wall of the box. The bottom end stop has grooves into which the teeth engage, preventing subsequent removal of the box. Thus the external front and back face of the box can have a plain, neat appearance.
JP-UM-55-93308 shows an arrangement in which a formation on the lower end of the box pin projects through a through-hole in the bottom wall of the box to secure the parts together.
JP-A-37-14329 shows an arrangement in which a tongue extends in from a side wall of the box to engage in a recess in the bottom stop.
Problems with these snap-fit designs are to provide a fixing which is not visible to the user so that it does not impair the visual impact of the open box, and also to provide a fixing which resists any movement of the box relative to the box pin since the box can be subject to quite strong lateral forces when the other end stop is inserted into the box.
JP-A-6-46906 shows a fixing in which the outer edge of the lower end of the bottom stop has a shoulder on its outside edge, which engages under a resilient leaf in the box.
JP-UM-6-38624 shows a fixing in which the lower end of the bottom stop is bifurcated. Shoulders on each outer side of the legs at the lower end engage under respective lips in the open box. The legs are urged toward each other as they are inserted into the box. These designs ameliorate some of the above-mentioned difficulties but still allow for axial movement of the box pin in the box.